Silicon conductive sandwich for pcb connections

[ringer]

My trusty Fluke 12 multimeter has, after 15 years of solid service, started playing up. It uses buttons to change the functions, and they are somewhat intermittent in operation. Opening up the meter it is constructed with a silicone keypad, not dissimilar to the ones found in mobile phones, and a pcb. To make an electrical connection between the two there is a rubber block which is I think silicone based, and it is constructed like a sandwich. Running down the middle of the block is a conductive layer which is split into five or six channels approx 2mm wide and which connect top to bottom. This block is positioned exactly under pads on the keypad and over pads on the pcb. The block is 13mm long by 3mm wide by 6mm high and covers five connector pads on the pcb. There is a much longer strip of the same material which connects the lcd screen to the pcb, but this is still working ok. I suspect that over the years the keypad connector block has become squashed and no longer touches both the keypad and the pcb simultaneously - hence the intermittent operation. I have temporarily resolved this problem by strategically placing a piece of cardboard inside the meter to force the keypad further in, but am lookin for a replacement part. Some research has found this and this which appear to be the product, but they are wholesalers and I only need a small bit. Does anyone know where I can source some of this conductive silicone sandwich?

I have contacted Fluke who passed me around a few departments and then told me the meter is obsolete and there are no spares for it. They will investigate it if I pay them £44 plus vat - with no guarantee they will fix it.

 

[grantr37]

you can get conductive silver paint in miniature bottles that goes on like a pen line, the printed flexible conductor you appear to mention does wear out over time and is also sometimes damaged by dampness if you leave your tools in an old van or a damp garage etc...

 

[rocker]

Go down the pound shop and buy one of the all in one remote controls they sell. Open it up and, if you've got the right one, you will find loads of the stuff. I use it all the time. Normally, if I'm repairing something, I cut off all the 'buttons', then you are just left with a big square flat piece that you can cut with scissors and glue to the bottom of your existing buttons. NOTE you may need to 'shave' the rubber part down a bit with a staley blade before gluing, as if it's too thick it will keep pressing the buttons when you don't want it to.